塔里木盆地塔深1井寒武系储层与成藏特征探讨

Discussion on characteristics of the Cambrian reservoirs and hydrocarbon accumulation in Well Tashen-1,Tarim Basin

云露 翟晓先

Yun Lu Zhai Xiaoxian

塔里木盆地塔深1井是中国第一深井,钻探目标是阿克库勒凸起东侧寒武系碳酸盐台地边缘的大型建隆圈闭。通过钻探,建立了奥陶系-寒武系地层层序。经证实,超深层建隆体内储层发育,储集空间类型多样,主要储集空间类型有晶间角孔、晶间溶孔和无结构选择性的溶蚀孔洞及网络状裂缝,并且储层呈随深度加深变好、溶蚀孔洞越发育的特征。初步认为,烃源岩生烃时排出的酸性流体产生的溶蚀是储集空间形成的主要因素;超深层(>7000m)建隆体具多期成藏的特征。特别是在岩心上和荧光薄片中见到液态烃,提示我们必须重新认识在不同地区(盆地)的特定地质条件下"液态窗下限"的问题。塔深1井的地质成果将有效指导塔里木盆地超深层勘探。

Well Tashen-1 is so far the deepest well in China.The well is designed to target at the large-scale build-up traps located at the edge of the Cambrian carbonate platform in the east of Akekule uplift,Tarim Basin. The stratigraphic succession from the Ordovician to the Cambrian has been built based on the drilling results of the well.It has been confirmed that quality reservoirs exist in the ultra-deep build-up.The types of reservoir space are various including intercrystalline pores,intercrystalline dissolved pores,non-structure-selective dis-solved vugs,and reticular fractures.As the burial depth increases,the reservoirs become more favorable and dis-solved vugs are better developed.It is preliminarily suggested that corrosion of the organic acid fluids discharged from hydrocarbon generation of source rocks be the main factor for the formation of reservoir space and that ultra deep(>7000 m) build-ups are characterized by multiple hydrocarbon accumulation.What is worth mentioning is that the liquid hydrocarbons observed on the cores and the fluorescence thin-sections may lead us to a re-un-derstanding of the lower limits of"oil-generating window"in different regions (or basins).It is also safe to con-clude that the geological fruits gained from Well Tashen-1 can be used effectively in guiding the exploration for ultra deep hydrocarbons in the Tarim Basin.

10.11743/ogg20080604